x1=[0.7	0.8	0.9	1	1.09	1.2	1.72	2.21	2.62	2.9	2.57	2.25	2	1.8	1.82	1.8	1.72	1.6	1.31	1.06	0.85	0.7	0.66	0.6	0.48	0.4	0.37	0.4	0.57	0.7	0.82	0.8	0.5	0.3	0.28	0.3	0.4	0.5	0.66	0.7	0.46	0.4	0.72	0.9	0.87	0.8	0.64	0.5	0.38]';
x2=[0.7073	0.838	0.9027	1.0334	1.103	1.2146	1.436	2.2418	2.6135	3.0363	3.0571	2.3466	2.239	1.8016	1.7888	1.8377	1.7474	1.6696	1.4942	1.086	0.9856	0.6824	0.689	0.6081	0.567	0.3734	0.4085	0.3195	0.4693	0.6511	0.7248	0.8866	0.6867	0.2961	0.289	0.2584	0.3315	0.4543	0.5283	0.7633	0.6023	0.2985	0.4894	0.9183	0.8435	0.8579	0.7043	0.545	0.4301]';
x3=[0.6863	0.8194	0.9758	1.0306	1.1638	1.2393	1.5247	1.6565	2.6686	2.9241	3.238	3.0824	2.4049	2.1674	1.7929	1.773	1.8196	1.7131	1.6275	1.417	1.0569	0.9447	0.6571	0.6727	0.5829	0.542	0.3595	0.389	0.302	0.4497	0.6187	0.7067	0.8583	0.6441	0.282	0.2719	0.2507	0.315	0.4327	0.5067	0.7279	0.5681	0.279	0.4672	0.8821	0.8045	0.8175	0.6717	0.5176]';
x4=[0.3526	0.6775	0.8154	1.0321	1.1811	1.2665	1.9344	1.9432	2.1256	2.0405	2.7529	2.6724	3.2668	2.7599	2.2633	2.1402	1.7479	1.6915	1.6963	1.5098	1.4942	1.3062	0.973	0.9063	0.6049	0.6007	0.5378	0.496	0.3299	0.3622	0.275	0.4309	0.5895	0.6173	0.7597	0.5743	0.2709	0.2542	0.2251	0.293	0.3902	0.4477	0.6612	0.5284	0.2587	0.4263	0.7928	0.7276	0.7344]';
num=length(x1);
res=0
for i=1:20
   res=res+(abs(x2(i,1)-x1(i,1))/x1(i,1));
end
res/40
plot(1:num,x1,'r+-',1:num,x2,'b+:',1:num,x3,'bo:',1:num,x4,'bx:');